Internal Impingement

1. Internal Impingement Em Antonogiannakis Orthopaedic surgeon Director Center for shoulder arthroscopy IASO General Hospital Athens www.shoulder.gr

2. Overhead athletes subject their shoulder to tremendous forces during competition • During the late cocking phase of throwing the arm may achive 170 to 180 degrees of ext. rotation to generate the torque required

3. Internal Impingement - Definition Injury and dysfunction due to repeated contact between the undersurface of the rot cuff tendons and the posterosuperior glenoid Walch JSES 1992 www.shoulder.gr

4. Internal Impingement Some contact between these structures is physiologic but repetitive contact with altered shoulder mechanics may be pathologic www.shoulder.gr

5. Internal Impingement For undefined reasons this contact in some athletes become pathologic and produces symptoms www.shoulder.gr

6. Internal Impingement Normally in abduction and external rotation (ABER) there is obligate posterior & inferior translation of the humerus that allows for more motion and less contact between the greater tuberosity and the posterosuperior glenoid rim www.shoulder.gr

7. Internal Impingement www.shoulder.gr

8. Mechanism of Internal Impingement Two major theories: • Andrew • Burkhart & Morgan May co-exist www.shoulder.gr

9. Mechanism of Internal ImpingementAndrew Theory: Dynamic stabilizers fatigue Increase stress to anterior & IGHL Repeated ABER Anterior capsule laxity to allow max ABER Internal Impingement Increased contact of undersurface of RC and posterosuperior glenoid Reduction of posterior & inferior translation of HH www.shoulder.gr

10. Mechanism of Internal ImpingementBurkhart & Morgan Theory: Superior translation of Humeral Head Repeated ABER Tight posterior capsule Internal Impingement Torsional stress to biceps anchor Increased contact of undersurface of RC and posterosuperior glenoid Peel-off Mechanism SLAP II and Pseudolaxity www.shoulder.gr

11. Internal impingement • SLAP lesions are not caused by internal impingement, they are rather the result of excessive torsional stress to the biceps anchor • Once produced SLAP lesions may increase the anterior translation of the humeral head up to 6 mm and the strain to the inferior glenohumeral ligament up to 100% www.shoulder.gr

12. Internal Impingement It is essentially an overuse injury associated with overhead athletes www.shoulder.gr

13. Internal Impingement • Typically symptoms are present only while playing • No symptoms with activities of daily living • Represents about 80% of the problems seen in the overhead athletes www.shoulder.gr

14. Internal impingement www.shoulder.gr

15. Internal impingement Throwing phases: www.shoulder.gr

16. Internal impingement Throwing phases: www.shoulder.gr

17. Internal Impingement Structures involved: • Humeral head • Anterior capsule • Inferior GHL • Posterior capsule • Rot cuff muscles www.shoulder.gr

18. Internal impingement – History • Chronicity of pain • Posterior pain • Abduction + external rotation aggravates pain www.shoulder.gr

19. Internal impingement – History • Insidious onset • Increases as the season progresses • Dull posterior pain • Worse at late cocking phase • Rarely can remember any traumatic episode • Loss of control and velocity www.shoulder.gr

20. Internal Impingement – Clinical Examination Inspection: • no rot cuff atrophy • no abnormality • Slight hypetrophy of muscles on dominant side www.shoulder.gr

21. Internal Impingement – Clinical Examination Palpation: • pain can be elicited over the infraspinatous • pain worse posteriorly than on GT, (vice versa on rot cuff tendonitis) • Anterior part of the shoulder, biceps groove and tendon are not painful. • No bony abnormalities. www.shoulder.gr

22. Internal Impingement – Clinical Examination ROM: • usually full range of motion • dominant arm tends to have • 10-15 deg more ext rotation and • 10-15 deg less internal rotation at 90 deg abduction • The most common for an overhead athlete is: • 2+ anterior laxity, • up to 1+ posterior laxity, • some inferior laxity, • but a firm endpoint www.shoulder.gr

23. Internal Impingement – Clinical Examination Provocative tests: • Neer’s test = negative www.shoulder.gr

24. Internal Impingement – Clinical Examination Provocative tests: Hawkins test = negative www.shoulder.gr

25. Internal Impingement – Clinical Examination Provocative tests: Cross arm adduction test = negative www.shoulder.gr

26. Internal Impingement – Clinical Examination Provocative tests: O’Brien’s test = negative (unless SLAP lesion) www.shoulder.gr

27. Internal Impingement – Clinical Examination Provocative tests: • Internal Impingement test = positive (patient supine, 90 deg abduction and max external rotation. If pain experienced at the posterior part of the joint = positive, 90% sensitive) • Relocation test = positive, (different from relocation test for anterior translation) www.shoulder.gr

28. Internal Impingement – Clinical Examination Relocation test of Jobe: Pain in the posterior joint line when the arm is brought in abduction external rotation with the patient supine that is relieved when a posterior directed force is applied to the shoulder www.shoulder.gr

29. Internal Impingement – Clinical Examination Muscles strength = normal www.shoulder.gr

30. Internal Impingement – MRI findings www.shoulder.gr

31. Internal Impingement – Differential Diagnosis • Rot cuff tendonitis or bursitis • Pain usually worse the day AFTER activity than DURING the actual event. • Typically deep soreness. • Unlikely internal impingement pain is more diffuse and not localized to the posterior aspect of the shoulder. • Difficulty in lifting the arm, pain at the GT, that improves with rest and NSAID after a short period. • Throwers’ exostosis (Bennett’s lesion). • Pain at the posterior part of the shoulder (more toward the inferior than the superior aspect of the shoulder). • Ceases with rest. • Radiographs can help (stryker notch view= calcification at the posteroinferior glenoid rim consistent with an exostosis). www.shoulder.gr

32. Internal Impingement – Bennett’s Lesion www.shoulder.gr

33. Internal Impingement – Differential Diagnosis • SLAP lesions • Pain more anterior than Internal Impingement. • Positive O’Brien test and SLAPrehension test. These tests are negative for internal impingement. • Coronal oblique MRI can help • Isolated posterior labrum tear • The most difficult to differentiate from internal imp. • Both posterior pain in the abducted and ext rotated position. • Arthroscopy can help www.shoulder.gr

34. Internal Impingement Why partial rot cuf tears are usually at the articular side? • Fewer arteriolars • Greater stiffness • Less favorable stress-strain curve www.shoulder.gr

35. Internal Impingement – Arthroscopic findings www.shoulder.gr

36. Internal Impingement – Arthroscopic findings www.shoulder.gr

37. Internal Impingement – Arthroscopic findings www.shoulder.gr

38. Internal Impingement –Treatment • Conservative • Surgical www.shoulder.gr

39. Internal Impingement – Conservative Treatment • Two main requirements for a good throw: • Large arc of motion • Adequate stability • Thrower’s paradox some laxity to static restrains => some degree of instability => muscles compensate • Fine balance is needed www.shoulder.gr

40. Internal Impingement – Conservative Treatment • Rest(complete stop of throwing is critical) • Rehabilitation(physical therapy as soon as possible) to • improve posterior flexibility • improve dynamic stabilization • increase strength of rot cuff muscles • Then gradual return to throwing • Improvement of throwing technique • +/- NSAID • Most athletes return to sport www.shoulder.gr

41. Internal Impingement – Surgical Treatment • Diagnostic arthroscopy (other pathology found…SLAP, biceps tendonitis, rot cuff tears etc) • Arthroscopic Debridement 25-85% return to pre-injury activity => effective ? www.shoulder.gr

42. Internal Impingement – Surgical Treatment • Open/Arthroscopic Capsulolabral Reconstruction • Arthrolysis of posterior capsule tightness • Repair of SLAP lesions • Repair of the rot cuff • Address anterior capsule laxity (50 - 81% pre-injury level) www.shoulder.gr

43. Internal Impingement – Surgical Treatment www.shoulder.gr

44. Internal Impingement – Surgical Treatment www.shoulder.gr

45. Internal Impingement – Surgical Treatment www.shoulder.gr

46. Internal impingement – Surgical Treatments infrequently Used Today • Arthroscopic Thermal Capsulorraphy Another method to reduce the anterior capsular laxity At the same time debridement + arthroscopic fixation of labral tears 86% return to pre-injury level • Rotational Osteotomy Derotation osteotomy of humerous => increase of retroversion + shortening of subscapularis => less impingement 55% return to pre-injury level www.shoulder.gr

47. Internal Impingement – Surgical Treatment Subacromial decompression • 22% of throwing athletes returned to the same level of participation after subacromial decompression Tibone ,Jobe. CORR 1985 www.shoulder.gr

48. Take home messages • Internal Impingement is a relatively common problem in overhead athletes • Difficult to treat • Caused by repetitive contact between the undersurface of the rot cuff and posterosuperior glenoid www.shoulder.gr

49. Take home messages • Initial treatment: • Complete REST + PHYSIOTHERAPY • If symptoms persists: • Multiple surgical techniques • Repair all lesions if possible www.shoulder.gr

50. Thank you for your attention www.shoulder.gr